This proposal is based on the theory that remodeling of the craniofacial skeleton is influenced by alterations in muscle activity. It is suggested that modification of sensory input affecting cranial reflexive pathways alters this muscular activity. This investigation attempts to define specific changes in craniofacial muscle activity during development of predictable morphologic changes in response to long-term alterations in sensory input. Two experimental models will be used. The two models are: 1) mouthbreathing rhesus monkeys in which the stimulus inducing oral respiration has been removed, and 2) rhesus monkeys adapting to long-term tactile stimulation of the tongue. Electromyographic recordings from selected craniofacial muscles are obtained as well as pertinent cephalometric measurements. Neuromuscular patterns will be determined for 16 craniofacial muscles during spontaneous activity and during elicited oromotor responses. The change in electromyographic activity will be analyzed using computer programs which rectify and integrate the total signal and quantify the level of activity. Morphological alterations will be determined by changes in vertical height, gonial angle, occlusal plane, palatal plane, and mandibular plane. The identification of specific neuromuscular patterns and changes in the activity will be correlated with the soft tissue and skeletal adaptations.